1. Field of the Invention
Aspects of the present invention relate to a hydraulic device, and more particularly to a hydraulic device including a spool valve.
2. Background of the Related Art
Related art hydraulic systems for applications in laparoscopic surgical tools, as well as tools for other surgical procedures, are known. However, current laparoscopic surgical instruments typically have considerable limitations, including those relating to their capability to access portions of the body obstructed by organs or other obstructions, and related art devices are typically difficult to sterilize. Furthermore, these devices often utilize straight bodies and/or other tools that that are awkward and difficult to use.
Moreover, related art laparoscopic surgical instruments typically use cables and hydraulic lines to manipulate the surgical tip of the instruments. The hydraulics often require the use of special hydraulic fluid that is not necessarily amenable to surgical environments or other special environments. For example, the use of conventional hydraulic oils in surgical environments is ill-advised and may create an assortment of hazards, especially if the system leaks or the hydraulic conduits are prone to rupture. While more medically compatible hydraulic fluid may be used (e.g., water, mineral oils), such fluid tends to evaporate at a significant rate. Monitoring and replenishing such fluid manually can be costly and labor intensive. Further, the consequences of not being vigilant concerning fluid levels could be severe, particularly in a surgical environment.
Moreover, related art laparoscopic surgical instruments using cables and hydraulic lines to remotely manipulate the surgical tip of the instruments can be vulnerable to accidental misuse or user overcompensation sometimes due to a lack of direct tactile feedback. This danger is particularly significant when the apparatus is not in deliberate use (e.g., dormant during a critical portion of surgery where other equipment is being used), is being serviced/stored or is not being operated by a skilled practitioner. Inadvertent and potentially damaging maneuvers are possible, for example, when the device is moved between operating theaters or when routine maintenance is being performed. In particular, problems can arise when a user moves a control for a laparoscopic surgical device in such a way that can cause damage either to the device itself, to ancillary devices and/or to the patient.
Thus, there is a need in the art for improved hydraulic devices, and more particularly, for improved hydraulic surgical systems.